The present invention relates to a device for shielding radio waves from an antenna board which transmits radio signals to IC chips provided on ink cartridges to be used in a recording apparatus such as an ink jet recording apparatus, and to the recording apparatus and a liquid ejection apparatus provided with the shielding device.
The liquid ejection apparatus herein described means not only the recording apparatus such as a printer, a copying machine, a facsimile employing an ink jet recording head and adapted to eject ink from the recording head to conduct recording on a recording medium, but also such an apparatus as ejecting a liquid suitable for its purpose, instead of the ink, from a liquid ejection head corresponding to the above described recording head to a target medium corresponding to the recording medium, thereby to deposit the above described liquid on the target medium.
As the liquid ejection head, there are mentioned besides the above described recording head, a coloring material ejection head which is employed in manufacture of color filters for a liquid crystal display or the like, an electrode material (electrically conductive paste) ejection head which is employed in fabrication of electrodes for an organic EL display, a face light emitting display (FED) or the like, a biological organic substance ejection head which is employed in fabrication of biological chips, a sample ejection head as a precision pipette, and so on.
In a non-contact type printer disclosed in Japanese Patent Publication No. 2002-127391A, cartridges containing a plurality of coloring media independently or integrally and having cartridge antennas corresponding to the coloring media incorporated therein are mounted on a carriage which is supported by a printer body so as to reciprocally move in a widthwise direction of recording, thereby to conduct printing by using the aforesaid coloring media. The carriage is provided with a body side antenna which is opposed to the cartridge antennas provided on respective cartridges, and the printer body is provided with a shielding plate made of electromagnetic shielding material which is inserted between a group of the cartridge antennas and the body side antenna when the carriage has arrived at a predetermined position. This shielding plate is provided with a window for sequentially permitting transmission and reception of signals between the body side antenna and the cartridge antennas, according to the movement of the carriage. The body side antenna has such a width that it can be opposed to all the antennas on a plurality of the cartridges mounted on the carriage.
The body side antenna is opposed to the respective cartridge antennas along with the movements of the carriage, and can make an access to a desired cartridge at a desired timing. When the carriage has arrived at the predetermined position, the aforesaid shielding plate will mask the cartridge antennas positioned at other places except the window, with respect to the body side antenna. On this occasion, transmission between the cartridge antenna which is not masked and the body side antenna is possible through the window.
However, in the above described structure, the body side antenna must have such a width that it can be opposed to all the cartridge antennas, and this will be a factor for hindering downsizing and cost reduction of components. Moreover, there is another problem that because the window of the shielding plate must be moved to an appropriate place to be masked according to the movements of the carriage, the structure will be complicated, and easily affected by manufacturing and assembling errors.
Further, in a type in which the ink cartridges are provided at the body side of the ink jet recording apparatus, it is also necessary to provide radio wave shielding function for the purpose of accurately exchanging information, for the reason that communication of the data must be conducted between positions of the IC chips of the ink cartridges and positions of connecting terminals in a communicating section.